1. Field of the Invention
The present invention relates to a device that aids in improving the quality of images formed with an imaging apparatus, and, more particularly, to a doctor blade for use with an imaging apparatus.
2. Description of the Related Art
An electrophotographic imaging apparatus, such as a laser printer, forms a latent image on a photoconductor member, such as a photoconductive drum, which in turn is developed by the application of toner to the photoconductor member. The electrophotographic imaging apparatus typically uses a developer roll to carry toner to the photoconductor member.
A doctor blade is used to meter the amount of toner that is to be carried by the developer roll to the photoconductor member, and ideally produces a thin, uniform layer of toner on the developer roll. For example, as the developer roll rotates, the developer roll carries toner to the doctor blade, which is spring biased into pressing engagement with the developer roll. The pressure that is generated in a nip between the doctor blade and developer roll causes the formation of a layer of toner on the developer roll, which in turn is carried to the photoconductor member.
Some known doctor blades used to meter toner have a coated metering surface. The coated metering surface, however, tends to be a rough, irregular surface. It has now been realized that such a rough, irregular surface for the metering surface of the doctor blade is prone to toner filming, due to the formation of toner agglomeration sites. When a sufficiently large amount of toner has agglomerated onto the metering surface, a resistive layer is formed, and thus, the toner charge is adversely impacted. As a result, toner may be developed in unintended places on the photoconductor member, resulting in background printing, such as in the form of a gray background, or streaks, on the print media, such as paper.
Also, the toner agglomerations at the metering surface of the doctor blade may be formed in irregular patterns, which in turn prevents a uniform toner layer from being formed on the developer roll, thereby resulting in streaks that are visible in the printed image.
What is needed in the art is a doctor blade, for use with an imaging apparatus, that is configured to reduce or eliminate toner filming on its metering surface, while promoting a uniform toner flow to the developer roll.